class Solution {
public:
	string intToRoman(int num) {
		string res;
		if (num > 3999) return res;

		vector<pair<int, string>> vt{ {1000,"M"},{900,"CM"},{500,"D"},{400,"CD"},{100,"C"},{90,"XC"},{50,"L"},{40,"XL"},{10,"X"},{9,"IX"},{5,"V"},{4,"IV"},{1,"I"} };
		for(auto elem:vt)
		{
			while(num-elem.first >=0)
			{
				res+=elem.second;
                num -= elem.first;
			}
		}
		return res;
	}
};